1. Field of the Invention
The invention relates to a vehicle pneumatic tire with a rubber tread having a profile which features blocks formed by circumferential grooves and by transverse grooves. At least some of the transverse grooves are limited by block flanks featuring flank segments that run at different angles to the radial direction.
2. Discussion of Background Information
A tire with such a tread rubber profile is known from JP 1-223 006 A. The tire has a profile composed of several block rows, whereby the block flanks that limit the circumferential grooves and the transverse grooves feature flank segments that run at different angles to the radial direction. The winter properties of the tire are thus to be improved.
It is known that the braking properties of a tire on a dry surface can be influenced by the stiffness of the tread rubber in the longitudinal direction. In order to improve the braking properties on a dry surface, it is therefore advantageous to provide tread rubber strips in profiles or, when using block rows, to embody the blocks to be as long as possible in the circumferential direction. These measures reduce the proportion of transverse grooves and thus also the number of block edges available, whereby the aquaplaning properties and the braking properties on a wet surface are impaired. It is further customary to orient the block flanks limiting transverse grooves at a rather small angle to the radial direction in order to keep the transverse groove volume as large as possible. This can lead to a greater stress and wear on those block edges, which are primarily stressed during braking. These effects, and the measures for influencing stiffness, are dependent on the direction of rotation of the tire. No effective measures for both directions of rotation have hitherto been available, particularly with tires which are not embodied with directional profiles.